Quick summary: Building Regulations Process
The Building Regulations Process is the route used to demonstrate that building work meets the legal standards for matters such as structure, fire safety, insulation, ventilation, drainage and access. For a typical home extension in England, it usually involves preparing technical information, choosing a building control provider, submitting an application, arranging inspections and obtaining a completion certificate.
- Check the work: confirm which parts of your project require Building Regulations approval.
- Choose an application route: normally Full Plans or, for suitable smaller projects, a Building Notice.
- Prepare the details: drawings, specifications and structural calculations may be required.
- Arrange inspections: Building Control must be notified at the relevant construction stages.
- Close the application: request the final inspection, submit the required completion information and retain your completion certificate.
Planning permission and Building Regulations are separate. A project may need both, one or neither, so it is important to check each requirement before work starts.
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What is the Building Regulations Process?
The Building Regulations Process is the system used to check whether building work complies with minimum legal standards in England. These standards cover important matters including structural stability, fire safety, energy efficiency, ventilation, drainage, electrical safety and safe access.
For a normal house extension, loft conversion or structural alteration, the process starts before construction and continues through the build. Building Control reviews the submitted information, inspects important stages on site and, when satisfied, issues a completion certificate.
What do the Building Regulations cover?
The detailed requirements depend on the work, but a domestic project may need to address:
- Part A: structural safety, foundations, beams, walls and floors.
- Part B: fire resistance, escape routes and smoke detection.
- Part C: ground conditions, moisture and damp protection.
- Part F: ventilation and indoor air quality.
- Part H: drainage and waste disposal.
- Part K: stairs, guarding and protection from falling.
- Part L: insulation, glazing and energy efficiency.
- Part P: electrical safety in dwellings.
The Government’s Approved Documents provide practical guidance on common ways of satisfying these requirements. However, they are not a substitute for a design that responds properly to your particular property and proposed work.
Building Regulations Process vs planning permission
Planning permission and Building Regulations approval are separate. Planning considers whether development is acceptable in principle, including its size, appearance, use and effect on neighbouring properties. Building Regulations focus mainly on how the work is designed and constructed.
Therefore, receiving planning permission does not automatically mean the technical construction details comply. Equally, some work may not require planning permission but may still require Building Regulations approval.
Our guide to the difference between the two approval systems explains this distinction in more detail.
Which Building Regulations application route should you use?
Most ordinary homeowner projects use either a Full Plans application or a Building Notice. Some installation work can instead be self-certified by a contractor registered with an authorised Competent Person Scheme.
Full Plans application
A Full Plans application normally includes technical drawings, construction notes, specifications and any necessary calculations. The information is checked before or during the early part of the project, and the building control body issues a decision.
This route is often suitable for extensions, loft conversions and more involved structural work because it gives the builder a clearer technical package. It also provides an opportunity to resolve compliance questions before the relevant work is covered up.
Building Notice
A Building Notice involves less information at the application stage and does not result in formal approval of detailed plans before construction. It can be suitable for some straightforward domestic work where the builder is experienced and the construction requirements are already clear.
However, Building Control can still request drawings, structural calculations or other evidence. If part of the work does not comply, it may need to be altered or rebuilt.
Read our comparison of Full Plans and Building Notice applications before choosing your route.
Competent Person Scheme
Certain types of installation work can be self-certified by an appropriately registered installer. Common examples include some electrical work, replacement windows, heating systems and insulation measures.
The installer normally notifies the local authority and supplies a compliance certificate. Nevertheless, self-certification only covers the work included within that installer’s scheme. It does not automatically approve the rest of a larger extension or conversion.
Building Regulations Process explained step by step
Although each project is different, the following sequence reflects the usual building control process for a house extension or domestic alteration.
Step-by-step Building Regulations checklist
- Confirm the work that needs approval. Check the extension, structural alteration, conversion or installation against the exemptions and notification rules.
- Appoint competent designers and contractors. Make sure the people responsible for design and construction have the right skills, knowledge and experience.
- Develop the technical design. Prepare plans, sections, specifications, insulation details, drainage information and structural calculations where required.
- Choose your building control provider. For most domestic work, this will be the local authority or a registered building control approver.
- Select the application route. Decide whether Full Plans, Building Notice or self-certification is appropriate.
- Submit the application and fee. Check that the property address, description of work, dutyholder information and supporting documents are complete.
- Respond to technical comments. Revise the drawings or provide clarification if the building control surveyor raises questions.
- Notify Building Control before starting. Follow the notice requirements given by your building control provider and confirm when work actually commences.
- Book inspections at the required stages. Do not cover foundations, drainage, insulation or structural details before the inspector has had the opportunity to examine them.
- Complete the final paperwork. Arrange the final inspection, provide certificates and submit the required completion notice or declarations.
- Obtain and retain the completion certificate. Store it with your drawings, calculations, warranties and other property records.
A detailed technical package is particularly helpful when builders are pricing the project. Our guide to the information normally shown on technical drawings explains what may be included.
Not sure what your Building Control submission needs?
We can prepare coordinated drawings and help you understand which calculations, specifications and supporting details are required.
How Building Control inspections fit into the process
Approval is not based on drawings alone. Building Control will normally inspect selected stages of the construction so the surveyor can assess work that may later become hidden.
Typical inspection stages
- excavated foundations before concrete is poured,
- foundation concrete and below-ground construction,
- damp-proof course and ground-floor preparation,
- below-ground drainage before it is covered,
- structural steelwork, beams or load-bearing alterations,
- roof structure and thermal insulation,
- fire protection and means of escape, and
- the completed project.
The exact inspection schedule is decided by the building control body and depends on the work. Your builder should coordinate visits, but as the homeowner you should still check that inspections have been requested and recorded.
Our separate guide explains what to expect when the surveyor visits.
What happens when the design changes?
Changes are common during construction. However, moving a beam, altering a roof, changing insulation or revising a drainage route can affect compliance.
Tell the principal designer, structural engineer and building control surveyor before the changed detail is built. Updated drawings or calculations may be needed, and agreeing the solution early is usually far easier than exposing completed work later.
How long does Building Regulations approval take?
For a Full Plans application, the normal decision period is five weeks, although it can be extended to two months with agreement. The time needed to prepare drawings and answer technical queries comes before or alongside that assessment period.
A Building Notice can usually allow work to start after the required notice period, commonly two working days after submission. However, this speed should not be confused with technical approval because the plans have not been formally approved beforehand.
The full process lasts until the work has been inspected, all requested evidence has been supplied and the application has been closed. Therefore, an extension application may remain active throughout the construction programme.
Quick costs snapshot
- Building Control charge: varies by provider, project type, size and inspection requirements.
- Technical drawings: normally priced separately from the Building Control charge.
- Structural calculations: may be needed for beams, foundations, retaining structures or altered load paths.
- Specialist evidence: energy calculations, drainage design, sound testing or air testing may add to the budget.
- Remedial work: late changes or non-compliant construction can create the largest unplanned cost.
Charges are not fixed nationally. Obtain a project-specific quotation and confirm whether plan checking, site inspections and completion are included.
Building Regulations fees sit alongside the design and construction allowances in your wider budget. See our complete guide to budgeting for an extension for the other professional, approval and building costs to consider.
Common Building Regulations Process mistakes
Starting before the design is coordinated
Beginning excavation while structural, drainage or thermal details are unresolved can lead to delay and expensive changes. A coordinated design gives the contractor clearer information and helps expose conflicts before work starts.
Missing an inspection
Foundations, drains and insulation can become impossible to assess once covered. Keep the inspection schedule visible and make one person responsible for booking each visit.
Treating approved drawings as optional
Builders may suggest an alternative detail on site. Some alternatives are perfectly workable, but they should be checked by the relevant designer and agreed with Building Control rather than adopted informally.
Forgetting the completion stage
A project is not properly closed simply because the builder has left. Outstanding certificates, test results, photographs or declarations may still be needed before a completion certificate can be issued.
Our guide to the evidence issued at the end of compliant work explains why this paperwork matters when selling or remortgaging.
FAQs: Building Regulations Process
What is the Building Regulations Process for a house extension?
It normally involves preparing technical drawings and calculations, selecting a building control provider, submitting a Full Plans application or Building Notice, notifying Building Control when work starts, arranging site inspections and obtaining a completion certificate when the work is finished.
Are Building Regulations mandatory?
They are mandatory where the proposed work falls within the controlled categories and is not exempt. Common examples include extensions, loft conversions, structural alterations, drainage work and certain changes to services. Some installations can be self-certified by a registered installer.
How long does a Building Regulations application take?
A Full Plans decision is normally expected within five weeks, or within two months where an extension of time is agreed. A Building Notice can allow suitable work to start sooner, but it does not provide prior approval of detailed plans. Design preparation and technical queries can add time before construction.
Can I start building before Building Regulations approval?
That depends on the application route and project. A Full Plans applicant can sometimes start before the decision, but doing so carries risk if changes are subsequently required. Under a Building Notice, work can usually begin after the required notice period. Always confirm the position with your building control provider before starting.
Do I need structural calculations?
Structural calculations are commonly required where walls are removed, steel beams are installed, roof loads change or foundation conditions need engineering input. Building Control may ask for them as evidence that the proposed structure satisfies Part A.
Who is responsible for arranging Building Control inspections?
The contractor often books the inspections in practice. However, the homeowner should confirm who is responsible, keep a record of visits and make sure work is not covered before the building control body has had the opportunity to inspect it.
What happens if building work does not comply?
Building Control may request further evidence, revised details, opening-up work or remedial construction. The safest approach is to raise design changes before they are built and to resolve inspection comments promptly.
What happens if work was completed without approval?
Depending on when the work was carried out and the circumstances, a local authority regularisation application may be available. Opening-up and remedial work may be required to demonstrate compliance. Specialist advice should be obtained before relying on retrospective approval.
Is a completion certificate important?
Yes. It records that, as far as the building control body could determine, the completed work complied with the applicable requirements. Solicitors, buyers, lenders and insurers may ask for it, so it should be retained with your property documents.
Have questions about your proposed work?
Share your project with Plans Made Easy and we’ll help you understand the likely drawings, approval route and inspection stages.
Next steps & useful guides
These related guides will help you plan the technical and approval stages in more detail:
- Read the complete homeowner overview of the legal standards
- Understand the role of the inspecting body
- Learn what goes into an application
- See what technical plans normally contain
- Prepare for inspections during construction
- Find out how to close the application properly
- Check when an engineer may be required
- Build a realistic extension budget
- Main purpose To demonstrate that building work meets minimum legal standards for safety, health, access and energy performance.
- Main application routes Full Plans, Building Notice or self-certification for qualifying work by a registered installer.
- Full Plans timescale Normally five weeks for a decision, or up to two months where the longer period is agreed.
- Typical documents Plans, sections, construction specifications, structural calculations and supporting technical evidence.
- During construction Building Control must be notified and given the opportunity to inspect relevant stages before work is covered.
- Final document A completion certificate should be obtained and retained with the property records.
- Important distinction Planning permission and Building Regulations approval are separate and may both be required.
Need help preparing your submission? Ask Plans Made Easy to review your proposed project.
Official guidance and further reading
Regulations and supporting guidance can change. Check the current official information before submitting an application or beginning work:
- GOV.UK guidance on choosing and making an application
- Government collection of current Approved Documents for England
- Planning Portal guidance on Building Control and approval routes
- Building Safety Regulator guidance on client, designer and contractor duties
Keeping the Building Regulations Process on track
A smooth Building Regulations Process depends on more than submitting a form. The design must be technically coordinated, the right evidence must be available and Building Control must be involved at the appropriate stages.
Before work starts, confirm your application route, appoint competent people and make sure the builder has a usable set of technical information. During construction, record design changes and arrange inspections before important work is hidden. Finally, close the application properly and keep every certificate.
Plans Made Easy helps homeowners prepare compliant drawings, coordinate supporting information and understand the steps from the first design through to completion.
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